Oven



1. C. WOODSON.

OVENl APPLICATION man o'cz 29, 1920.

'1,428570, Patenasept. 12,1922..

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wrrNEssE's; lNvEN'roR JJM/maf l Jagd C Woaab'an Patented sept. 12, 1,922.

UNITED :STATES PATENT orrlce.

JAMES C. WOODSON, OF MANSFIELD, OHIO,ASSIGNOR TO 1Ji/'Et'llGtHOUSE ELECTRIC PRODUCTS COMPANY, A COROR-ATION OF MICHIGAN.

`OVEN.

Applicaton'filed October 29, 1920.

T 0 all 207mm it may concern:

Bc it known that I, JAMns C. WooDsoN, a citizen of the United States, and a resident of Mansfield, in the county of Richland and State of Ohio, have invented a new and useful Improvement in Ovens, of which the following is a specification.

My invention relates to ovens and particularly to ventilated ovens, and it has for its object. to provide relatively simple means A,for reducing the heat-radiation losses in such an oven.

In practising my invention,. I provide a plurality of sets of walls for an oven chamber and place heatinsulating material ben tween the walls of each set` and spacing blocks between the sets of walls. I provide Ventilating openings in the inner set and in the outer set of walls, these ventilating openings being located in delinite spaced relation to each other. I provide means for causing a delinite circulation of air from theoven chamber through the Ventilating openings in the inner set ot walls, through the space between the sets otwalls, and either out into the surrounding space, or back intol the oven chamber, withan admixture of fresh air, it "desired In the single sheet of drawings,

vFigure 1 is a view, in vertical cross-section, ol' an oven embodying my invention, and

Fig. 2 is a cross-sectional view of the oven on the line II II of Fig. 1.

An oven chamber 1 is surrounded by side walls 2, end walls 22a bottom wall', and a top wall 4l. These walls may be of any desired or suitable construction, but, as shown in Fig. 1, comprise plates oi relatively thin sheet metal and suitable heat-insulating material located therebetween.

A plurality of ventilating openings 5 is provided in the top wall 1, and a Ventilating opening 6, located in the bottom wall 3, is provided with an adjustable damper 7, to permit of varying the eiiective area of the opening.

A second set of walls 8, comprising spaced sheet metal plates and heat-insulating material therebetween, is located in spaced relation to the walls 2, 3 and t. Suitable spacing members 9 are provided to maintain the two sets of walls in definite spaced relation,

Serial No. 420,393.

providing paths for the heated fluid that flows through the Ventilating openings 5 from the chamber 1.

An opening 10 is provided in one of the walls 8, this opening being substantially diametrically opposite one of the openings 5. An exhaust pipe 11 is located in the opening 10 and is provided, at its outer end, with an adjustable damper 12 to permit of varying the effective area of the passage.

An electrical heating means 13 is provided which may be oi any suitable construction and which may be controlled in any suitable or desired manner.

In order to obtain a positive circulation of heated fluid into and out of the oven chamber 1, I provide a ventilating fan 14 which may be driven by a suitable motor 15. The in-tale of the fan 14 is suitably connectedto the exhaust pipe 11 by means of a. pipe or tube 16, an adjustable damper 17 being'provided to permit of varying the amount ofair withdrawn from the exhaust pipe 11.

I provide a pipe 18 that is connected to the pipe 16 between the damper 17 and the fan 14 to permit of adding fresh air in any desired quantity. The exhaust sidev of the fan 14 is connected to the oven chamber 1 by means of a pipe or tube 19, suitable pro vision, comprising a plurality of spaced openings 19a, being made to insure that the fluid pumped through the pipe 19 shall vbe .distributed as equally as possible over the entire volume of the oven chamber.

If it is desired to rely upon the natural circulation of the heated iiuid out of the oven chamber 1 and through the ventilating openings 5, it is only necessary to entirely close the damper 12 and to open the damper 7, without operating the Ventilating fan 14; a constant flow of Huid will then circulate from the oven chamber 1, through the ventilating openings 5, through the space between the inner and outer set of walls and through the opening 6, back into the oven chamber. If it is desired to add a certain amount of fresh air, this may be done by opening the damper 12 to a predetermined position. It it is desired to ventilata the oven chamber withouthaving the heated fluid return thereto, it is only necessary to close the damper 7 and to open the damper 12.

It it is desired to cause a forced circulation of fluid, the motor 15 may be energized to operate the fan 14 at any desired or suitable speed. In order to cause a circulation of heated Huid without any ad-mixture,

it is only necessary to close the dampers 7 and 12 and to open the damper 17 in the pipe 16, with the damper 2O in the pipe 18 entirely closed. If the damper 20 be partially open, a predetermined amount of fresh air will be drawn in and added to the heated fluid being circulated by the fan 14. If it is desired to cause a forced circulation of heated fluid without recirculation thereof, that is, to ensure that all the heated fluid shall pass through the oven-.chamber only once, the dampers 7 and 17 may be closedv and the dampers 12 and 20 may be opened.-

The temperature of the fluid flowing through the space between the two sets of walls will be only slightly lower than the temperature of the fluid in the oven chamber 1, and hence, only a small amount of heat will escape through the inner set of walls. Substantially all of the heat radiated vfrom the outer surface of the oven, that is, from the outer surface of the walls 8, will be provided by the heated fluid which is located in the spaces between the two sets of walls.

In a Ventilated oven, a certain part of the heated fluid from the oven chamber is, of necessity, permitted to escape to the outer atmosphere, and the use of the device embodying my invention permits of causing this heated fluid to. surround the oven proper as a definite envelope of live heated fluid.

Practically all of the heat radiated from the i I claim as my invention:

1. In a Ventilated oven, the combination with a set of walls enclosing a chamber and having Ventilated openings, heat-insulating material located between said walls, and

heating means for said chamber, of a second set of walls located outside of said first mentioned walls and having a Ventilating opening located on the side of said oven opposite to said first mentioned Ventilating openings, heat-insulating material between said walls, spacing blocks of relatively small area for spacing said sets of walls apart, the Ventilating openings and-the space between the sets of' walls being so connected as to permit of supplying subst'antiallyI all of the heat-radiation losses of theA oven from the heated fluid flowing through the said Ventilating openings and said space.

2. In a Ventilating oven, the combination with a plurality of sets of spacedapart sets of Walls surrounding achamber and provided with Ventilating openings, heat-insul lating material between certain of said walls,

and heating means for said oven chamber,

of means ,for causing a circulation of heated 4fluid through said Ventilating openings and between certain of said walls, and means for permitting a predetermined quantity of said heated fluid to flow into the atmosphere.

3. In a Ventilated oven, the combination with a plurality of A`sets of spaced-apart sets of walls surrounding a chamber, Ventilating openings in said sets of'walls, heatinsulating material between certain of said walls, and heating means for said oVen chamber, of means for causing a circulation of heated fluid through said Ventilating openings and betweencertain ofsaid walls, means for permitting a predetermined quantity of said heated fluid to flow into the atmosphere, and means for permitting a predetermined -quantity of fresh air to be introduced into said oven chamber.

AIn testimony whereof, I have hereunto Subscribed my name thisl 20th day of Oct., y

' JAMES C VOODSON. 

